1. Field of the Invention
The invention relates to a fuel cap which is to be attached to a filler neck which is open for a fuel supply, and particularly to a fuel cap through which static electricity accumulated in the human body or clothes of a person can be discharged.
2. Description of the Related Art
A conventional fuel cap is configured in the following manner as shown in FIG. 1.
A fuel cap 2 comprises a closure 3 which is formed by a synthetic resin such as polyacetal, and a shell 14 which covers the upper part of the closure 3 and which is formed by a synthetic resin such as nylon.
The closure 3 comprises a cylinder portion 4 which is substantially cylindrical, and a ceiling portion 8 which is disposed so as to close an inner periphery of the cylinder portion 4 at a substantially center position in the vertical direction. A flow path hole 9 is opened at the center of the ceiling portion.
A thread portion 5 which is to be screwed into a filler neck 1 is formed on the outer periphery of the cylinder portion 4. A flange portion 6 which is engaged with a shell 14 is formed on the outer periphery of the upper part of the cylinder portion 4. A seal ring 7 is attached to the lower face of the flange portion 6.
A valve element 10 which constitutes a negative pressure valve is disposed on the side of the lower face of the ceiling portion 8 in the cylinder portion 4. The valve element 10 is held by a valve element holding plate 11 which is upward urged by a coil spring 12.
The coil spring 12 is supported by a spring seat plate 13.
As shown in FIG. 1, the thus configured fuel cap is to be attached to the filler neck 1 which is disposed in a fitting hole 17 formed in a mounting panel 16 below a fuel lid 15 of an automobile. In the figure, 18 designates the body of the automobile, 19 designates a fuel supply port, and 20 designates a main unit of the body of the automobile.
However, the conventional fuel cap is not provided with a function of, each time when the cap is opened or closed, discharging static electricity accumulated in the human body or clothes of a person.